Commit 7a05be8c70 for qemu.org

commit 7a05be8c70bb789c23076b1ca2563ed7d87c6fb8
Author: Cédric Le Goater <clg@redhat.com>
Date:   Mon Jan 12 17:33:50 2026 +0100

    tests/rcutorture: Fix build error

    Newer gcc compiler (version 16.0.0 20260103 (Red Hat 16.0.0-0) (GCC))
    detects an unused variable error:

      ../tests/unit/rcutorture.c: In function ‘rcu_read_stress_test’:
      ../tests/unit/rcutorture.c:251:18: error: variable ‘garbage’ set but not used [-Werror=unused-but-set-variable=]
        251 |     volatile int garbage = 0;
            |                  ^~~~~~~

    Since the 'garbage' variable is used to generate memory reads from the
    CPU while holding the RCU lock, it can not be removed. Tag it as
    ((unused)) instead to silence the compiler warnings/errors.

    Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
    Link: https://lore.kernel.org/qemu-devel/20260112163350.1251114-1-clg@redhat.com
    Signed-off-by: Cédric Le Goater <clg@redhat.com>

diff --git a/tests/unit/rcutorture.c b/tests/unit/rcutorture.c
index 7662081683..2f19d479a3 100644
--- a/tests/unit/rcutorture.c
+++ b/tests/unit/rcutorture.c
@@ -248,7 +248,7 @@ static void *rcu_read_stress_test(void *arg)
     int pc;
     long long n_reads_local = 0;
     long long rcu_stress_local[RCU_STRESS_PIPE_LEN + 1] = { 0 };
-    volatile int garbage = 0;
+    volatile int garbage __attribute__ ((unused)) = 0;

     rcu_register_thread();